Belt-like support means are used in many elevator installations. Such support means generally comprise a plurality of tensile carriers which consist of steel wires and which absorb the tension forces to be accepted by the support means. The tensile carriers are in general surrounded by a casing of synthetic material.
Such support means are a safety-relevant component within an elevator installation. For this reason, use is made of checking units in elevator installations which check, in particular, the mechanical state of the tensile carriers. Damage to the tensile carriers absorbing the forces shall thereby be able to be recognized in good time. The support means can thus be exchanged in the event of damage so as to prevent failure of the elevator installation.
The electrically conductive tensile carriers are surrounded by the electrically insulating casing of synthetic material. In order to carry out a check of the state of the tensile carriers electrical contact is usually made with the tensile carriers and, with the help of an electrical test current conducted through the tensile carriers, the state of the tensile carriers is ascertained. In that case, changes, especially an increase in the electrical resistance of the tensile carriers, indicate deterioration of the state of the tensile carriers. In order to be able to reliably check the individual tensile carriers it is important that the tensile carriers are not in electrical contact with one another. Such electrical short-circuits between tensile carriers of a support means can arise at, for example, locations at which the support means is clamped in place.